Pressure adjustment in rotary printing machines



H. GERLACH Aug.- 15, 1950 PRESSURE ADJUSTMENT IN ROTARY PRINTING MACHINES Filed Dec. 29 1945 I Zeal.

Patented Aug. 15, 1950 .Hugo Gerlaohjfiendon, London, England, as-

' signor tol'Bloek Anderson Limited; London,

England? a' British"company ApplicatihmDecembenflQ, 1945, ,Serial No 1538;179. InGreat Britain April 16; 1945- invention relates to rotary printing.v machines'embodying alprinting couple, consisting t of a rotatable printing .cylinder. or drum and? a rotatable pressure 01: platen roller," and is 4 appIi cable with. particular advantage. "to spirit reproducing. machines in which a mirror-script.

master is mounted" upon the printing, cylinder and copies are taken on. copy, sheets 'or a web passed between the printing cylinder and the cylinder. with even pressure and uninterrupted contact .-aIng the entire efi'ecti've axiall'eng'th thereof and so that-"the. pressurebetween the roll'en and cylinder can he evenly adjustedal'ong'" theienti'relaxialilengthi the manipulation offa' single control;

8 Another object of; the invention ist'o provide means. for applying the. pressure roller to theprinting. cylinder in such a manner'that the pres:-

sure roller'can be set simply and'quickly many of" a. number of predetermined" pressure values and, as readily removed from contact 'W'rththe' 7 work or printing roller "by'manipnlation of a single control;

p further-"object ofthe invention istoprovide a printing machine construction in which thepressure roller 'or'platerr 'is'urge'd towards the printing cylinderiby a' forcetransm'rtted through a; system of levers, the pivots of"whiclr'are'journa'li'ed in open bearings" so disposed that the"- reaction of the operating forces transmitted through" such lever" system serve toretain the journalledmembersin proper position;

Yet a furtherobject 'otthe-invention iste-provide an arrangement as: last" recited'in which the system oi levers is arranged to possess inherent'resil'ience suflicient to" provide a suitahle" yielding pressure upon said pressure -or platen" roller by appropriate positive location ofthe 0p- 7 posite end of'said lever system'withouttheintem position of; additional" spring or like resilient pressure exerting, means. I

Qther objects of'the invention will'he apparent 2; from the foll'owing, detailed" description 'of one constructional embodiment now to be given by way of example withreference to the accompanying drawings in which:

Fig. l is.a diagrammatic representation ofthe printing couple of a v rotary (printing machine of the spirit duplicating type embodying pressure cylinder mechanism" according "to' the present invention and" Fig.2. is a diagrammatic plan view offthe a1.- rangcment shown 'in-"Fi'g'; 11

Reierringzto the drawings, "to, I I" indicatethe base 'andside frames ohthe machine, 12 the printing cylinder or drum; an'd13'thepressure platen roller", whichrismourrted uponza: spindlert journal'ledat its endsin plain bearing blocksfffi of'the open top or half: hearing type. Bearingj brackets IGare formedmtegralwith; orsecureii'. to", the side-frames fl and arranged slidablrto" support the bearing blocks 15 downwardly opening" 'gui'de. channel's "so"that' the hi ooks are freelymovable in a direction normal to "the" axis ofrotation'of' the prihtingjcylin'der. Alternative ly; the endspf" spindle f4" may-hejvournalled in ball or roller-bearings which could he carried in" blocks 01'" frames adaptedsiidabiy-to engage in bearingbrackets l6;

The-lower end" of'eaetrbearinlgblock 1"5 is: slotted seas'freefwto, the ends of a lift bar' I 'Iwhich extends betweenthe blocks I and is provided on-fits lower" edge: at thecentral point between the 'hearing 'lolocks, a cup- 1 6 to" receiveabaEt-"W; A' thrust screw" 20-; pro--- vided with an enlarged headfor engagement with the ball IS in the-manner" of a =universahthrust coupling; is screwedinto' an arm-"21 which is "formed" integral with, or fixed" to; atransverserock shaft '22; thethrust screw'being" set in its position-of ad-jhstment hy meansof a= lockingmnt 24-; The-shaftZE, which constitutes the pivot of a lever system, iournalled i 1-1= ha1hbearings== 23 Y w-hi'ch are secured to; or termed integrallwith the side frames I' I and ydisposed so 'that the-roclt shaft lies parallel with the axis of thepressure roller t3.

Alever- 25 of appreciable length is" keyed; -01" otherwise secured, torock shaft so as to ex tend parallel to, and adjacent the'inner wallof one-oi the-side-frames Hi Thelever'fifinstapered? in Width fora-purpose hereinafter"descrih'ed and o carries; at-"its free-end; a roller w-hich isjeun" nalled uponapin 21" so as to" project outwards from the side of the lever and towards the" ad'- jacent side frame" I" I1 A hand lever 28" ispivotally secured by pin"??? to the inner wall of the side frame I I immediately above the free end of lever 25 so that the lower cammed end of the hand lever engages roller 26. A series 01 notches 30 having their centres upon an arc eccentric tothe point of pivotation of hand lever 28 are formed'in the lower cammed end of the latter to'receive roller 26, and anear 3| is provided at the end of the notched part of the lever to prevent the latter from being turned beyond the useful limit of its movement. Alter: natively, or in addition to the ear 3|, a stop (not shown) may be provided upon the frame II to limit the movement ofthe hand lever. The tapering of lever 25, made from spring steel, enhances the degree of resilience of this member so that by suitable setting of thrust screw 29 a spring loading of the lever system can 4 roller into yielding contact with said printing cylinder comprising a first order lever of spring material in engagement at one end with said pressure roller and at the opposite end with adjustable rigid stop means positioned to stress said lever and journal bearings for the fulcrum pivot of said lever comprising open half-bearings 8 so disposed that the reaction of the forces operbe achieved to maintain the roller 26 in contact with hand lever 28 and yieldingly to urge pressure roller l3 into contact 'with the work or printing cylinder i2 with a suitable degree of pressure and resilience to provide proper printing operation without the'need of interposing additional means such as springs or the like.

'The functioning of the invention is obvious from the foregoing description and need be no more than briefly recapitulated; By placing the hand lever into the full line position shown in Fig. 1 and then adjusting thrust screw 26 in arm 2! so as to bring the pressure roller l3 into light contact with the printing cylinder [2, the mechanism is set so that movement of the hand lever, notch by notch, towards the position shown in chain-dot outline will depress the free end of lever arm 25 and raise arm 2|, thrust screw 2:? and lift bar ll, thus to move the slidable bearing blocks 15 upwards in their guide brackets 16 so that the pressure roller i3 is applied to the printing cylinder lid with progressively increased pressure as the stressing of the lever arm 25 is increased while the entry of roller 26 into any of the notches 33 serves to retain lever 28 against inadvertent movement from the position in which it is set. Furthermoraby reason of the universal thrust coupling between arm 2i and lift bar ii at the geometrical centre of the distance between the bearing blocks, the pressure roller is applied to the printing cylinder with substantially equal pressure along the entire length of their contacting surfaces. By movement of the hand lever in the opposite direction beyond the full line position shown in Fig. 1 the pressure roller can be permitted to break contact with the work or printing cylinder.

The reaction of the forces applied in the operation of the mechanism firmly retain the pressure roller spindle l i and'rock shaft 22 in their supporting half bearings which in turn facilitate the rapid and easy assembling and dismantling of the mechanism as and when required by allowing the removal of arm 2|, shaft 22 and lever 25 and then the roller I3 by the simple expedient of releasing the lever 28 from contact with the roller 26 and then lifting the parts out without having to remove any other elements such as bearing caps, set screws or guide covers.

The invention is not restricted in its application to spirit duplicating machines and constructional modification and developments of the above described practical embodiment may be devised within the ambit of the appended claims.

I claim:

1. In a rotary printing machine, a printing cylinder, a pressure roller for cooperation withsaid printing cylinder, means for urging said pressure ating upon said lever system serves to retain the pivots in position in said half bearings.

. 2. In a rotary printing machine, a printing cylinder rotatably mounted in a machine frame,

' arotatable pressure roller for cooperation with said printing cylinder, said pressure roller being jou'rnalled at each end in floating bearings slidably mounted in said machine frame for movement towards and away from the surface of said printing cylinder, a rigid bar member extending between each of said floating bearings, mean for urging said pressure roller into yielding contact with said printing cylinder comprising a first order lever' having one arm in engagement at its free end' with the mid-region of said rigid bar memher and having its second arm formed as a resilient leaf spring in engagement at its free end with rigid stop means positioned to stress said leaf spring arm, and journal bearings for the pivots of said lever system comprising open halfbearings so disposed that the reaction of the stress applied to said leaf spring serves to retain the pivots in position in said half-bearings.

3. In a rotary printing machine in accordance with claim 2, the provision of manually adjustable means for regulating the pressure applied to urge said pressure roller into contact with said pressure cylinder and comprising mechanism for altering the position of said rigid stopmeans in engagement with the free end of said leaf spring arm of said lever whereby the latter is made capable of being stressed to different degrees.

' e. In a rotary printing machine in accordance with claim 2, the provision of manually adjustable means for regulating the pressure applied to urge said pressure roller 'into contact with said pressure cylinder and comprising mechanism for altering the position of said rigid stop means in engagement with the free end of said leaf spring arm of said lever whereby the latter is made capabl'e of being stressed to different degrees, said mechanism being in the form of a hand lever pivotallymounted upon the machine frame and provided with a cammed surface divided into a series of notches each of different radial distance from the pivot of said hand lever and position so as to be 'engageable selectively with an abutment formed on said free end of said leaf spring lever arm.

5. A rotary duplicating machine comprising a machine framework having opposed side frame members, a rotatable printing cylinder journalled in said side frame members and extending transversely therebetween, a rotatable pressure roller disposed parallel to said'printing cylinder and having projecting spindle pivots at each end, bear ing blocks of the open half-bearing type for receiving and supporting the spindle pivots of said pressure roller, bearing brackets on each of said side frame members for slidably supporting said bearing blocks for movement in directions towards and from the surface of said printing cylinder, .slots in said bearing blocks at the ends thereof opposite to those having the open halfbearing surfaces, a bar member extending transversely of the machine and engaging at each of its ends in said slot's,'a cup-shaped depression the icenter of said' -bar member on the side thereof opposi teto that facing said pressure roller, aloose ball seated in saiddepression, a rock shaft disposedtransversely between said side frame members, an arm projecting radially from the center-region of said rock shaft and. carrying a thrust screw having a head surface positioned to-=engagesaid loose-ball and thereby to exert pressure through said bar memberequally to each of said-"bearing blocks-so as tourge said pressure rollerinto contact with said printing cylinder when said rock shaft is constrained to-rotate in a chosen direction, an extended-lever arm of springmaterial'secured at one of itsends to said rock shaft near one end-ofthe latter, a manually adjustable position stop device in engagement with the other end of said extended'leverarm and serving, through theflex-ing ofsaiclextended lever arm-- tourgerotation of said rock shaft so as to impart pressure to said ball, and journal bearings for the opposite ends of saidrock shaft, said jourrial;- bearings being carried upon said side frame members andcomprising open-half bearings so disposed that the reaction of the pressure force exerted upon said pressure roller serves to retain the ends of said rock shaft properly seated in said half bearings. i

'6; A- rotary duplicating machine comprisingv a machine framework having opposed side frame members, arotatable printing cylinder journalled in-said sid'e frame members. and extending trans-- versely therebetween, a rotatable pressure roller disposed parallel toandbelow said printing cylinder and having projecting spindle pivots at each end, bearing blocks slidably mounted on each of said side frame members for up and down movement in a vertical direction open half-bearing surfaces at the upper ends of each of said bearing blocks, a bar member disposed transversely of the machine and engaging at each end with the underside of one of said bearing blocks, a rock shaft also disposed transversely of the machine between said side frame members, a short stiff arm projecting radially from the mid-region of said rock shaft to one side thereof and carrying a universal thrust coupling device engaging the mid-region of said bar member for exerting upwardpressure thereto by appropriate rotation of said rock-shaft, an extended lever arm of spring material secured to said rock-shaft, means for applying pressure to the free end of said extended lever arm so as to stress said arm to constrain said rock-shaft to rotate in said appropriate direction and journal bearings for the opposite ends of said rock shaft, said journal bearings being carried upon said side frame members and comprising open half-bearings so disposed that the reaction of the pressure force ap plied through said lever system serves to retain the ends of said rock shaft properly seated in said half-bearings.

7. A rotary duplicating machine in accordance with claim 6 wherein said extended lever arm of spring material is disposed so as to lie at the opposite side of said rock shaft relative to said short stiff radially projecting arm and wherein said journal bearings for said rock shaft consist of blocks secured to said side frame members and provided upon their uppermost surfaces with open half bearing surfaces.

8. A rotary duplicating machine in accordance with claim 6 in which said extended lever arm of spring material is tapered towards its free end.

9. A rotary duplicating machine in accordance with claim 6 in which said extended lever arm of a! spring material i'sisecured to' saidrock-shaftinear oneend of the latter and ispositioned toi lie. closely adjacent one side frame member of the machine frame.

10.- A rotary-duplicating machine comprisinga machine framework having opposed side frame members, a rotatable printing cylinder journaled in said: side'frame members and V extending transversely' therebetween, a rotatable pressure roller disposed parallel to and below said printing cylinderand having projecting spindle pivots at each end, bearing blocksslidably mounted oneach 'of said side frame membersforup: and down movement in a vertical direction, open half-bearing surfaces at the upper-ends of each-of said bearing blocks, a bar member disposed transversely of the machine and engaging at each end with the underside of one of said bearing blocks, a rock shaft-also disposed transversely ofthe ma:- chine between said side frame members-, an arm projecting radially" from the mid-region of" said rock shaft to one side thereof, a thrust screwhaving a plane head surface andthreaded into an aperture in said radially-projecting arm at a positionwhere said plane head faces said bar mem-- her, a cupshaft depression formed of the lower surface of said-bar member opposite said head of said screw, a loose ball secured in;said' depressionbetweensaidbar member and saidhead, an extended lever arm secured to said rock-shaft; means for applying pressureto' the opposite end of said extended lever arm so -as to constrain said rock-shaftto rotate in a direction to exert upward pressureupon said barmember through said ball and journalzbearings forthe opposite ends of said rock-shaft, said journal bearings being carried upon said side frame members and comprising open half-bearings so disposed that the reaction of the pressure force applied through said lever system serves to retain the ends of said rock shaft properly seated in said half-bearings.

11. A rotary duplicating machine comprising a machine framework having opposed side frame members, a rotatable printing cylinder journalled in said side frame members and extending transversely therebetween, a rotatable pressure roller disposed parallel to and below said printing cylinder and having projecting spindle pivots at each end, bearing blocks slidably mounted on each of said side frame members for up and down movement in a vertical direction, open half-bearing surfaces at the upper ends of each of said bearing blocks, a bar member disposed transversely of the machine and engaging at each end with the underside of one of said bearing blocks, a rock shaft also disposed transversely of the machine between said side frame members, journal bearings for the opposite ends of said rock shaft and comprising open half-bearings carried upon said side frame members and disposed to resist downward movement of said rock shaft, an arm projecting radially from, the mid-region of said rock shaft to one side thereof and carrying a universal thrust coupling device engaging the mid-region of said bar member for exerting upward pressure thereto by appropriate rotation of said rockshaft, an extended lever arm secured to said rockshaft, means for applying pressure to the 0pposite end of said extended lever arm so as to constrain said rock-shaft to rotate in said appropriate direction, said pressure applying means comprising a hand lever pivoted on one side frame member and provided with a cammed portion divided into a series of notches each of different radial distance from the pivot of side hand lever and Z which are successively engageable by an abutment carried by the free end of said extended lever arm.

12. A rotary duplicator machine comprising a machine framework having opposed side frame members, a rotatable printing cylinder journalled in said side frame members and extending transversely therebetween, a rotatable pressure roller disposed parallel to and in peripheral contact with said printing cylinder and, having projecting spindle pivots at each end, movable bearing means engaging said projecting spindle pivots for carryingsaid pressure rollers in a bodily move able manner whereby said roller may be moved radially towards or away from said printing cyl inder, lever mechanism including a resilient element associated with said bearing means for moving said pressure roller towards said printing cylinder, a hand lever pivoted in said machine framework and provided with a cammed portion divided in a series of notches each of different radial distance from the pivot of said hand lever, an abutment carried by said resilient lever mechanism for engagement with said series of notches whereby the engagement with said series of notches whereby the engagement pressure between said pressure roller and said printing cylinder may be adjusted by altering the position of said pivot hand lever to cause said abutment to be engaged by a difierent one of said notches and thereby to strain the resilient means of said lever systemto a different extent.

in said side frame members and extending transversely therebetween, a rotatable pressure roller disposed parallel to said printing cylinder and in peripheral engagement therewith, movable bearing means for said pressure roller, said bearing means being movable to cause said pressure roller to move in a radial direction towards or away from said printing cylinder, a hand lever pivoted transversely within said machine'framework, said hand lever comprising a cammed portion divided into a series of spaced notches each of diiferent radial distance from the pivot of said hand lever, a lever arm of spring material pivoted in said machine framework and carrying an abutment engageable with one or the other of the notches of said hand lever portion and pressure-transmitting means interconnecting said lever arm and said bearing means for said pressure roller. HUGO GERLACH.

REFERENCES CITED The following references are of file of this patent:

UNITED STATES PATENTS record in the 

